Giant Olympic Rings were unveiled on Tower Bridge this morning.

The Mayor of London Boris Johnson, London 2012 chief Seb Coe and the City of London Corporation’s Stuart Fraser watched from a boat in the centre of the Thames as the Rings were lowered into place.

The Rings weigh more than three tonnes and measure more than 25 metres wide and 11.5 metres tall.

A new, energy-efficient lighting system will bring them to life, and an illuminating light show will take place this evening to mark their installation.

Mr Johnson said: “Glorious Tower Bridge is recognised the world over and, adorned with the famous Olympic Rings, is the perfect choice to showcase what London has to offer this summer. With just a month to go, we are making our final preparations and want to ensure each and every person in the capital gets a flavour of the celebrations and feels part of the Games.”

The rings are part of the mayor’s city-wide Look and Celebration programme, which includes free events and shows across all London boroughs and which aims to showcase London to the world.

Mr Johnson said: “Our fantastic – and free – cultural festival will be springing up in every London borough, with more surprises over coming weeks so prepare to be delighted, wherever you are in the capital.”

During the Games, across London from Hungerford Bridge to London Bridge, each of London‘s famous bridges will also be lit up in a display of colour during the evenings and the giant mobile Olympic rings first seen in March will return to the river travelling up and down stream past its famous waterfront landmarks.

Lord Coe, chairman of the London Organising Committee of the Olympic and Paralympic Games (LOCOG), said: “The Olympic Rings are an iconic symbol, inspiring athletes and uniting people around the world.

“To athletes they represent the culmination of thousands of hours of training and reaching the highest level in sport. With one month to go to the Olympic Games opening ceremony these spectacular Rings on one of London’s most famous landmarks will excite and inspire residents and visitors in the capital.”

Following the end of the Olympics, the Rings on Tower Bridge will be replaced by the Paralympic Agitos.